How to answer the world's toughest interview questions

You’ve researched the company, prepared your answers, even found out a bit about the CEO… and then they go and ask you about a giraffe. could you handle the world’s toughest interview?

Words: Kate Graham

England’s World Cup hopes may be dashed, but this week a handful of men and women will be inside the team’s changing room, giving ‘players’ (actors, in full England kit) the pep talk of their lives. Their goal isn’t international glory, but a top job.

In what has been dubbed ‘The World’s Most Creative Job Interview’, candidates for the role of creative entrepreneur, who will run a banking division at Virgin Money, will, among other tasks, have to prove they can motivate a demoralised team.

The world of job interviews has definitely changed. Joe Wiggins, PR manager for career website Glassdoor, is witnessing a trend in increasingly hard interviews. “Some questions test a candidate’s values and some are lobbed in like a hand grenade to see how a candidate reacts under pressure,” he explains. “In many cases there is no correct answer, but there may be a right way to respond.”

We’ve scoured the globe for 24 of the toughest real interview questions from the world’s top companies – see how you fare…

1. How do you fit a giraffe in a fridge?

“The interviewer wants to see if you overcomplicate something simple,” says Jane Sunley, author of It’s Never OK To Kiss The Interviewer …And Other Secrets To Surviving, Thriving And High Fiving At Work. “Usually it’s followed up with, ‘And how do you fit an elephant in a fridge?’, as they’ll be testing for recollection of previous actions. The answer they’re looking for is: you open the fridge, put the giraffe in and close the door. To fit the elephant in, you open the fridge door, take out the giraffe, put the elephant in. Simple.” Not shrinking it in a magic machine then? Gotcha.

2. Would you rather fight a horse-sized duck or 100 duck-sized horses?

“This is testing your ability to weigh up different options before deciding on the right one,” says Rachel Spedding, managing director of graduate career site Bright Network. “A good answer considers both animal physiology and your own tactics to achieve victory. We’re ideally looking for someone to plump for one side, showing that even under pressure you have the conviction and confidence to make a choice. You should show creativity and hunger to win, especially if the interviewer argues back.”

3. How many planes are there currently in the air?

“This is a process question so we can see how people think through problems,” says Peter Goldstein, global head of human resources at ITG. “We’re looking for candidates who aren’t rattled by pressure. We’d like to see them take their time, articulate some logical assumptions (for example, how many people worldwide travel by aeroplane?) and do some simple calculations to come up with a thoughtful and at least plausible solution. Blurting out, ‘One billion aeroplanes!’, would probably bring the interview to a quick end.”

4. How would you describe an atom to a child?

“This is about taking a tricky concept and communicating it simply and with clarity,” says Vicky Oliver, author of 301 Smart Answers To Tough Interview Questions. “I’d say something like, ‘An atom is the smallest building block for all things. Imagine you have a bowl of vanilla ice cream, which is largely made from eggs, sugar and cream. An atom is the same as one granule of sugar.’”

5. How lucky are you and why?

“With this question, we are testing a candidate’s attitudes towards risk and control,” says Nick Wilkins, head of communications in Europe for the lodging rental website. “People who consider themselves unlucky tend to blame factors outside of their control. People who think they are lucky generally feel more in control of what they do, and are more motivated and positive. They’re also more entrepreneurial, an important factor for us.”

6. How many pound coins would it take to match the height of Big Ben?

“This is mathematical,” says Jim Harvey, communications manager at myjobmatcher.com, but is also designed to test problem-solving abilities and quick thinking. “Clarify if it’s lying flat or on their edge. Now for the trick. Big Ben is, of course, the bell, not the tower. Big Ben is 2.28 metres tall. A pound coin is 3.15mm thick. Therefore, the answer is 724 (723.8) coins.” Although, you obviously wouldn’t be expected to know the real dimension. That would just be odd.

7. If you were shrunk to the size of a pencil and put in a blender, how would you get out?

William Poundstone, author of Are You Smart Enough To Work At Google? answers, “I would jump out. If I were the size of a pencil, my muscles would be much stronger relative to my weight, just as they are for fleas and grasshoppers. A creature’s weight is proportional to the cube of height, while muscle strength is proportional to the square.”

8. How many ways can you get a needle out of a haystack?

“This question is looking for you to solve a problem creatively,” says John Lees, author of The Interview Expert: How To Get The Job You Want. “Demonstrate your ability to come up with a range of ideas quickly: If the needle is steel, a magnet will do the trick. Metal will react differently to other stimuli – ultrasound, or a radar device perhaps? Or you could simply burn all the hay and the needle will remain.”

9. What do you think about garden gnomes?

“This is about having an opinion that’s sensible and rational,” says Sunley. “You could answer: they make healthy profits for gnome manufacturers – margins are good since they keep producing the same traditional styles and models. They’re reliable workers – out in all weathers, lifting wheelbarrows and fishing for goldfish.”

10. If you were a brick in a wall, which brick would you be and why?

Reverse engineer the interviewer’s intentions, says Poundstone. “It takes many bricks to make a wall, just as it takes many employees to make a company. This question is about teamwork. The most important brick isn’t the biggest or the strongest: it’s the one that works best with the other bricks, takes weight from above and transmits it below.” Of course it is.

11. How many grains of sand make a heap?

“With this question I’m looking to see how the candidate will react,” says Abigail Stevens, managing director of Think Global Recruitment. “There’s no one correct answer, it’s the delivery that’s important. This question can also tell you what kind of thinker your candidate is; will they give you a logical answer or a slightly more creative one? Then I can make a choice about who is a best fit for the role advertised.”

12. You’re in a row boat, which is in a large tank filled with water. You have an anchor on board, which you throw overboard (the chain is long enough so the anchor rests completely on the bottom of the tank). Does the water level in the tank rise or fall?

“This is actually a very tough problem, unless you’re applying for a sailor or physics faculty job, no reasonable interviewer will expect the right answer” says Kador. “The trick is not to get flustered. Quality response: ‘The key here is whether the displacement caused by the anchor in the boat is more or less than the displacement of water caused by the volume of the anchor in the water.’ At this point, you've nailed the response. The rest can be calculated or intuited. Guess and it all will be fine, there's a 50% chance you'll be right. For what it's worth, the water level will go up.”

13. If you could be anyone else, who would you be and why?

“The ‘why’ is critical here, because candidates will throw out a list of qualities that they themselves feel are important,” says Monika Fahlbusch from Salesforce.com, who devised the question. “When they're smart, they figure out an example that has the qualities that align most to the organisation’s need. Is the person an innovative big thinker, an inspirational leader or someone who's giving back to the world? Knowing what you admire and aspire to helps us determine if you’re the right fit for us."

14. How many people travel on a tube each day?

“I want to see evidence of thinking on your feet and logic,” says Kirstie Mackey, Head of LifeSkills at Barclays. “I’d never expect the exact answer. The best candidates use logic to work out a potential answer and talk me through how they got there. For example, there are roughly 8 million people in London as a base, but how many tourists are likely to visit and how many more might commute in? They might even take into consideration what season or the day of the week it is.”

15. What are five uses of a brick, not including building, layering, or a paper-weight?

This question needs to be answered fast says Oliver, as it’s really testing how quick you are on your feet. “Remember the answers don't matter. You’re given parameters so as long as you follow the rules (and logic) if the question, you should be fine. If it were me, I’d say:

A weight to carry at the health club

A yardstick to measure a room's dimensions

A door jam to keep a door open or prevent it from slamming shut

A weight goal (to lose)

A hot plate to keep pizza warm

16. What makes you angry?

“This throws every candidate,” says Spedding. Some people give tangible reasons (a hot tube or a late bus), others can be more sweeping and say ‘lateness full stop’ or ‘messiness’. “Of course, all of these answers suggest that someone is conscientious but the question is more about probing a candidate's self-awareness. As it’s such an unexpected question, it’s also an excellent way to see how a candidate thinks analytically about themselves – on their feet. How a person goes about answering it is often more interesting and telling than the actual answer.”

17. If I put you in a sealed room with a phone that had no dial tone, how would you fix it?

“Freezing makes an interviewer worry about your ability to improvise under pressure,” says Lees. “The trick is to question assumptions. Your answer might be ‘It’s a mobile phone. It doesn’t have a dial tone.’ Cover the basics: ‘First I’d make sure it’s connected to a phone line and power.’ Show you’re astute by asking probing questions about how big the problem is, and whether being in a locked room should take priority over making a phone work. There are no right answers, simply good opening gambits.”

18. How many tennis balls can fit in this room and why?

This is a standard gross order of estimation question, says Kador. “First and foremost, the interviewer wants to see you react with playful curiosity and intellectual interest. They want to see a problem-solver. They don’t want to see someone who gets flustered. Say ‘Let's see, the room is about 10 x 12 x 10, so that's a volume of 1,200 square meters. I suppose 100 tennis balls can fit in a square meter, so that means 12,000 tennis balls.’”

19. Given 20 ‘destructible’ light bulbs (which break at certain height), and a building with 100 floors, how do you determine the height that the light bulb breaks?

The key is to work in intervals, says Oliver. “Start at floor 10. If the light bulb breaks, go down floor by floor until it doesn't break. If it doesn’t break, go up to floor 20 and repeat, and so on. Again this is a rest of your logical thinking and process.”

20. If the time is 11:50, what is the angle between the two hands of the clock?

“This tests your ability to make fairly simple calculations under pressure,” says Harvey. “The easy trap to fall into is to think that at 11:50, the minute hand is on the 10 and the hour hand is on the 11 and give the answer 30 degrees. However, because the hour hand moves continuously, one needs to apply the following logic...

There are 360 degrees in an hour, 60 minutes in an hour and, therefore 6 degrees in a minute. There are 30 degrees between the hour markers on a clock face, therefore, the hour hand moves at the rate of 30 degrees per hour. At ten to the hour, the hour hand will have completed five sixths of its 30 degree journey [30x5/6 = 25. Therefore, when the minute hand rests on the '10' at 11:50 the interior angle between the two hands is 55 degrees. Notice I said 'interior' angle because someone will always point out that you didn't specify it in the question and show off by asking for clarification or giving both answers (305 degrees for the exterior angle by the way).”

21. If I told you that, on average, Japanese women are shorter than UK women, how would you confirm it

You could show logical thinking and explain how to calculate this statistically, suggests Sunley, using average heights of various nations on the internet. Or you could get more creative. “Suggest calling Diesel or Levi's and asking what distribution of jeans they sell around the world. Except for the possibility that leg length isn't an exact indicator of height they should be able to tell you how tall people are in any given country based on the jeans they sell there.”

22. How do you weigh an elephant without using scales?

This question, attributed to IBM, is about logical thinking says Poundstone. Here’s his answer:

1. Lead the elephant onto a barge, ferry, or other ship big enough to support it.

2. Make a mark on the hull showing the water level.

3. Lead the elephant off the barge. The barge will of course rise up in the water.

4. Now load the barge with 100-pound sacks of sand. Keep loading until the barge sinks back to the water mark made in step 2.

5. The elephant weighs as much as the bags of sand.

23. Can you instruct someone how to make an origami germ catcher using only words?

There’s no ‘right' answer says Amanda Warwick, HR Director of Living Social who uses this question. They like to see that candidates play along, show a creative side in crafting a response, and give us some insight into their problem solving process. “The content of the answer itself isn’t all that important. Rather, we are looking for a candidate to be able to effectively communicate their response—however bizarre—in a manner that is clear, logical and methodical.”

Experts:

Jane Sunley, author of It's Never OK to Kiss the Interviewer: and other secrets to surviving, thriving and high-fiving at work